报告题目：Novel functions of multidrug efflux pumps in bacterial stress response to low oxygen tension
报  告  人：Aixin Yan， Assistant Professor
School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
报告时间：6月28日下午2：00
报告地点：生物楼树华多功能厅
组织单位：微生物分子生态学与生态基因组学实验室
hbs红宝石平台

报告摘要：
Multidrug efflux pumps are well known for their capability of actively removing antibiotics out of cells and causing antibiotic and multidrug resistance in bacteria. However, the fact that efflux genes are widely distributed in the genomes of all living organisms and constitute from 6% to 18% of all transporters in the rather compact genomes of bacteria suggests that this class of gene products have important functions in bacterial physiology in addition to their roles in causing resistance to antibiotics. The E. coli K-12 genome contains 37 efflux genes encoded in its 20 efflux systems. Yet except for the housekeeping AcrAB-TolC efflux system, the expression, function, and physiological roles of the rest of efflux genes are poorly understood. In this talk, I will present our study on the 20 efflux systems of E. coli under its anaerobic growth conditions, an environmental signature of the mammalian gut and the anaerobic micro habitat of bacteria in nature. We identified a dramatic up-regulation of an additional efflux pump MdtEF under this condition and found that this multidrug efflux pump has a physiological function of defending the bacterium from reactive nitrogen species (RNS) during its lifestyle in the anaerobic ecological niches.

报告人简介：
Assistant Professor (07/2008-present): The University of Hong Kong, Hong Kong
Postdoctoral Fellow in Molecular University of Wisconsin-Madison 04/2006-06/2008
Biology & Microbiology with professor Patricia J. Kiley
Postdoctoral Fellow in Biochemistry Duke University Medical Center 06/2005 -04/2006
with professor Christian R. H. Raetz,
Postdoctoral Fellow in Biochemistry SUNY Stony Brook 10/2001- 05/2005
& Cell Biology with professor William J. Lennarz
Ph. D. in Bio-Organic Chemistry Peking University, China 07/2001
with professor Yun-hua Ye